New not sure if this is where you put it. But anyway what kind of fencing do you have? I have 3 big horses then a mini that are horrible at respecting the fence. Prices would help too and maybe pictures thanks :)
I have 4 strands of white electric rope attached with screw in insulators to treated wood posts. The top and third strands are electrified and the horses don't go near it. I think I have zapped myself far more often than the horses have. Clearly, they have learned to respect it much faster than I have.
Cost, installation and maintenance are all quite low.
We have a 5' high four board fence...Heavy Duty!! Like literally, you could keep bulls in there but, that's just my Dad's style...Maybe try putting an electric hot wire on your current fencing...? that ought to keep them off it.